Dark Energy
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you're right. I was wrong! damn - I'm as confused as when I found that the Hubble constant isn't!
PooperPig - Coming Soon
Not your fault. There's so much written on the topic using such poorly crafted language that it's not surprising that people get wrong ideas.
I wanna be a eunuchs developer! Pass me a bread knife!
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So does light travel in a ray or does it not
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_Maxxx_ wrote:
Well (as I'm sure you know) what actually happens is someone formulates a theory and observations support it or otherwise.
Indeed, but what troubles me is that the observations are of such tiny amounts of light/radio waves, that have traveled God knows how far and through God knows what (e.g. if it travels through a tiny patch of blue dust, in the billions of miles between here and its source, it becomes more yellow), so grand assumptions simply cannot be made. But grand observations are made, nonetheless, and compounded with further grand assumptions, then backed up with numbers that are tailored to fit, until we have a model of the universe that makes very little sense, and is constantly being challenged by observations that are "more accurate" because they are backed up by three photons more than the previous observations. And nowhere along the way does anyone admit that it's all guesswork -- they call it "great, new discoveries", rather than admit it's all guesses. We need more data, not more guesses. Guessing is easy, but getting it right requires more than 2000 photons per month.
_Maxxx_ wrote:
For Example, the regular dimming of a star's light together with evidence of a perceived 'wobble' (detected by changing dopler shift) could be caused by something other than a planet orbiting - but these are real, repeatable measurements and the theory fits.
But so would a thousand simpler theories -- i.e. plain ol' boring dust or temperature gradients could far more easily be proven to be the cause of wibbles. But that wouldn't make people famous or get them big research grants, would it? And when a few more quanta of the EMS arrive, which should easily prove that something else is the case, they'll just "massage" their Grand Unprovable Theories to make them fit the new data.
I wanna be a eunuchs developer! Pass me a bread knife!
Quote:
tiny amounts of light
The Hubble Ultra-Deep Field Image, a study of galaxies as old as 13.5 billion years at distances up to 60,000 light years was a composite of 288 exposures of approximately 20 minutes. Many degrees of magnitude more than 2000 photons collected in considerably less than a month I would suggest!
I am not a number. I am a ... no, wait!
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Quote:
tiny amounts of light
The Hubble Ultra-Deep Field Image, a study of galaxies as old as 13.5 billion years at distances up to 60,000 light years was a composite of 288 exposures of approximately 20 minutes. Many degrees of magnitude more than 2000 photons collected in considerably less than a month I would suggest!
I am not a number. I am a ... no, wait!
But that's not what we're talking about. We're talking about the (was it five or six?) novae at Extreme ranges that were used to cobble together the ridiculous "dark energy" theory. 60,000 light years is just down the road.
I wanna be a eunuchs developer! Pass me a bread knife!
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Human mind was created to enable us to survive on earth. To find food and mate for reproduction. Explaining a concept beyond 3 dimensional space as "curved" is still using 3 dimensional concept. God doesn't owe us a "how" answer in human words. Our brains are not ready.
The approach taken by superstring theorists is to add variables to represent motion in additional spatial dimensions. So while they cannot visualize in ten dimensions, by extension they can still calculate the behavior of particles moving in that many dimensions. The problem is to avoid topological defects such as magnetic monopoles (particles that emit a magnetic field at rest). This is an amusing point in relativity theory: we know that a charged particle in motion curves under the influence of a magnetic field. But what if we shift to a reference frame that moves along with the particle. If the particle is at rest in that frame, there is no velocity, and so no force exerted by the field. The answer is that the fields themselves are also altered by the change of reference frame: in the particle's rest frame, there is an electric field that cause it to accelerate. Similar things happen in General Relativity. One of the side effects in rolling up higher-dimensional spaces (to produce our three-dimensional reality) is that magnetic field lines can be forced into spatial rifts, which then appear as magnetic monopoles. A brilliant Indian mathematician "proved" (I'm not sure anybody understands the proof) that avoiding magnetic monopoles requires that the universe sit in ten or eleven spatial dimensions. That current theory opts for the "ten" option may have something to do with the seven seals in the Book of Revelation. I'm not aware of any theoretical reason for the choosing ten over eleven. Much as Gell-Mann named his model of particle zoology the "eight-fold way" as a reference to Buddhism, my paranoid brain is half-convinced that some theorist chose ten because at the "end of days" that would mean the seven "sealed" dimensions would open upon our return to the Godhead - matching the number of seals on the scroll opened by the lamb.
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Just thought-experimenting. If (as often happens) we represent 'spacetime' as a flat sheet (usually black rubber with white grid lines) and the distortion of spacetime by mass as a large ball sitting on the sheet, we can show the effect of gravity by rolling a smaller ball along the sheet, which will accelerate toward the large ball, and (ignoring friction) collide with or orbit. So far so good. In this model the flat sheet is suspended in 'nothing'. But, what if you 'zoomed out' and the sheet was actually curved? Imagine it is sitting on a massive sphere. If the sphere grows, so the 'universe' will expand. Indeed if the sheet itself were like the skin of a massive rubber ball, then this effect would be observed if the ball was inflated. So what we call 'dark energy' could simply be the inflation of whatever it is that 'supports' the universe. The turtles are sliding down the side of the shell. [^]
PooperPig - Coming Soon
Maxxx: Your extension of the "rubber sheet" metaphor is an valid way of visualizing the action of the cosmological constant. So I think that you're providing a useful analogy to explain its action, rather than suggesting an alternative. My own position regarding dark energy is rather more revolutionary, and motivated by a far simpler proposition. Dark Energy cannot be moving at all speeds in all directions. Since it interacts with regular matter, it therefore establishes a preferred reference frame. Einstein's theories of special and general relativity go out the window. So I think that physics has gone on a long detour since 1860, when the Michelson-Morley experiment was done. This was an experiment that sought for evidence of the "aluminiferous ether" - the medium in which light waves traveled - by measuring the change in the velocity of light as the earth circled the sun. It did not detect any change, and so physicists adopted the view that space was empty. But there's another explanation: the speed of sound does not vary as the earth circles the sun, because the air is entrained with the motion of the earth. Dark Energy must be entrained with matter and carried along with it as it moves. This allows a whole lot of interesting possibilities for explanation of general relativistic effects. Brian
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Human mind was created to enable us to survive on earth. To find food and mate for reproduction. Explaining a concept beyond 3 dimensional space as "curved" is still using 3 dimensional concept. God doesn't owe us a "how" answer in human words. Our brains are not ready.
Actually, I will argue a Lizard Brain was created for these things. The human mind was created with an additional ability to recognize ever increasing complex patterns. Plus the ability to use pattern compression (like a cross between fractal and zip compression), and once again, re-iterate the pattern recognition process. Mix in a little bit of curiosity, and a few free cycles to notice the world at varying levels. And we eventually stumble across communications and science. Communication only works because the definition of things like CUP is relatively fixed and contextually determinant (Sports vs. drinking). So. I argue that we are designed to SEE patterns. Including ones that we do not yet understand (Gravity), and then we find ways to study them (lasers?) until we can produce devices that manipulate what we see. Once we are there, our endless creativity at trying different things (testing conjectures) until voila, we find something (spinning magnets) that appear to manipulate the gravity we see via lasers... Until we get a unique result. Wash, rinse, repeat. So, it is REALLY hard to explain a 4th or 5th dimension to someone who truly only sees 3 dimensions. But I will argue it becomes easier to mathematically accept an n-th dimension when we know how to manipulate it to get a non-linear result in 3D space. Meaning. We will get there! And given a billion years of evolution, testing, recording, I would only take the counter bet because I would not live long enough to pay the winner!
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Just thought-experimenting. If (as often happens) we represent 'spacetime' as a flat sheet (usually black rubber with white grid lines) and the distortion of spacetime by mass as a large ball sitting on the sheet, we can show the effect of gravity by rolling a smaller ball along the sheet, which will accelerate toward the large ball, and (ignoring friction) collide with or orbit. So far so good. In this model the flat sheet is suspended in 'nothing'. But, what if you 'zoomed out' and the sheet was actually curved? Imagine it is sitting on a massive sphere. If the sphere grows, so the 'universe' will expand. Indeed if the sheet itself were like the skin of a massive rubber ball, then this effect would be observed if the ball was inflated. So what we call 'dark energy' could simply be the inflation of whatever it is that 'supports' the universe. The turtles are sliding down the side of the shell. [^]
PooperPig - Coming Soon
If you want to learn more about Dark Matter and Dark Energy, read the book "Dark Side of the Universe" by Iain Nicolson. It's pretty technical and filled with charts and graphs but nothing the people in this forum couldn't comprehend. It's also a little dated - astronomy/cosmology have progressed as fast as computer hardware and software in the past 20 or 30 years (largely because of advances in computer hardware and software). There are mountains of data that support the current theories of General Relativity, Dark Matter, Dark Energy and the existence of planets around other stars. Those theories have evolved as more data is gathered. The community of astronomers and cosmologists is as dedicated, hard-working and objective as the community of coders/developers. No more and no less. Conspiracy theories about astronomy have about as much validity as conspiracy theories about the latest version of C++.
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Be nice. Calculus isn't included in computing courses.
I wanna be a eunuchs developer! Pass me a bread knife!
Yes it is, computer engineering has calculus, physics, electronics, etc. A lot of it
To alcohol! The cause of, and solution to, all of life's problems - Homer Simpson ---- Our heads are round so our thoughts can change direction - Francis Picabia
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Mark_Wallace wrote:
They are light
Search google for 'a ray of manure' ... you'll get a hit og two ;)
Espen Harlinn Chief Architect - Powel AS Projects promoting programming in "natural language" are intrinsically doomed to fail. Edsger W.Dijkstra
Ray of manure? My aunt was married to him. Stinky old walking piece of Sh.t.
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Just thought-experimenting. If (as often happens) we represent 'spacetime' as a flat sheet (usually black rubber with white grid lines) and the distortion of spacetime by mass as a large ball sitting on the sheet, we can show the effect of gravity by rolling a smaller ball along the sheet, which will accelerate toward the large ball, and (ignoring friction) collide with or orbit. So far so good. In this model the flat sheet is suspended in 'nothing'. But, what if you 'zoomed out' and the sheet was actually curved? Imagine it is sitting on a massive sphere. If the sphere grows, so the 'universe' will expand. Indeed if the sheet itself were like the skin of a massive rubber ball, then this effect would be observed if the ball was inflated. So what we call 'dark energy' could simply be the inflation of whatever it is that 'supports' the universe. The turtles are sliding down the side of the shell. [^]
PooperPig - Coming Soon
That is how curved spacetime is commonly viewed since Einstein. The model about galaxies moving apart is not the problem. However, since measurements have shown that the galaxies not only move apart, but also accelerate doing so, the big question is what drives that acceleration? The only force we know that works to any measurable effect at cosmic distances is gravitation, but gravitation is an attractive force, whereas what we see appears to be some kind of repelling force. This force is called dark energy, and, so far, we have not the faintest idea what it is, or where it comes from. One idea *I* have been considering is that there is no repellant force after all. Instead, there could be something beyond the visibility horizon that attracts the far removed galaxies - through gravitation. We already know that continued inflation will eventually fling the visible galaxies so far apart that we will no longer be able to see them, or even realize there are such galaxies outside our field of vision. We cannot be sure that this isn't already the case! So, what if the brunt of the mass of our entire universe is already beyond our field of vision, and what if the outermost galaxies are already rebounding due to the cumulated gravity of the entirety of the universe? This would cause a relatively strong concentration of mass close to the real (invisible) boundary of the universe that may have a stronger gravitational effect on the galaxy that are close to the boundary than the cumulated gravitaty of the 'inner' galaxies. I'm not sure how to model this mathematically though, and have some doubts that such a scenario is even possible - if it were, I'm sure some scientists would have worked it out by now. Another possible explanation I could think of is based on the inflating rubber ball analogy: think of god as a 'little' girl, who tried a little too hard to inflate a five dimensional balloon until it burst? That burst is the big bang, our universe is not the (four-dimensional) surface of the balloon (which existed before), but the (3-dimensional) fringe of the tear! The force that apparently speeds up the expansion of our universe in truth is the contractive force of the rubber balloon that pulls the fringes of the rubber away from the origin of the burst :cool: Ok, I don't think that theory will hold up to scientific scrutiny either, but at least it is fun working out the details. Also it is a much more realistic story of creation than any contemporary religion can offer. Unfortunately, it
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That is how curved spacetime is commonly viewed since Einstein. The model about galaxies moving apart is not the problem. However, since measurements have shown that the galaxies not only move apart, but also accelerate doing so, the big question is what drives that acceleration? The only force we know that works to any measurable effect at cosmic distances is gravitation, but gravitation is an attractive force, whereas what we see appears to be some kind of repelling force. This force is called dark energy, and, so far, we have not the faintest idea what it is, or where it comes from. One idea *I* have been considering is that there is no repellant force after all. Instead, there could be something beyond the visibility horizon that attracts the far removed galaxies - through gravitation. We already know that continued inflation will eventually fling the visible galaxies so far apart that we will no longer be able to see them, or even realize there are such galaxies outside our field of vision. We cannot be sure that this isn't already the case! So, what if the brunt of the mass of our entire universe is already beyond our field of vision, and what if the outermost galaxies are already rebounding due to the cumulated gravity of the entirety of the universe? This would cause a relatively strong concentration of mass close to the real (invisible) boundary of the universe that may have a stronger gravitational effect on the galaxy that are close to the boundary than the cumulated gravitaty of the 'inner' galaxies. I'm not sure how to model this mathematically though, and have some doubts that such a scenario is even possible - if it were, I'm sure some scientists would have worked it out by now. Another possible explanation I could think of is based on the inflating rubber ball analogy: think of god as a 'little' girl, who tried a little too hard to inflate a five dimensional balloon until it burst? That burst is the big bang, our universe is not the (four-dimensional) surface of the balloon (which existed before), but the (3-dimensional) fringe of the tear! The force that apparently speeds up the expansion of our universe in truth is the contractive force of the rubber balloon that pulls the fringes of the rubber away from the origin of the burst :cool: Ok, I don't think that theory will hold up to scientific scrutiny either, but at least it is fun working out the details. Also it is a much more realistic story of creation than any contemporary religion can offer. Unfortunately, it
Interesting thoughts - I"ve certainly known some 5 year olds who *thought* they were god! Acceleration is the change in velocity over time. And velocity is change in position over time. So - what if it is *time* that is changing ? If, in fact, from their own POV every distant star, galaxy etc. are moving at a constant velocity, but from our POV time slows as a function of distance, then they would appear to be speeding up. This would make sense also from a space-time expansion perspective. Space expands and time contracts by way of conservation of energy. Simples!:cool:
PooperPig - Coming Soon
